Catalytic dehydrogenation of organic compounds



Patented Oct. 13, 1931 Qumran STATES v PATENT OFFICE ALrHoNs 0. JAEGER, or GRAFYTOK, PENNSYLVANIA, ASSIGNOR 'ro THE sEnnEN com- PANY, or rrr'rsnonen, PENNSYLVANIA, A GORIPORATIQN or DELAWARE CATALYTIC DEHYDROGENATION OF ORGANIC COMPOUNDS No Drawing. Original application filed April 3, 1928, Serial No. 267,134. Divided and this application file April 1, 1929. Serial No. 351,826;

- This invention relates to the splitting ofi ofhydrogen from organic compounds. Examples of these dehydrogenation reactions are the dehydrogenation of alcohols to aldegghydes and ketones, for example methyl alcohol to formaldehyde, cyclohexanol and its dc:

new class of catalysts. The contact masses used in the present invention contain base :5.exchai'1ge bodies or their derivatives. Under the term base exchange body are included all natural or artificial bodies which possess the properties of ex'changingtheir bases for other bases of salt solutions. The base exchanging products used in making catalytic compositions of the present invention or as initial material for derivatives to be so used may possess high base exchanging power or inmany cases may possess lower base exchanging power, since the catalytic valueof the final composition is not primarily dependend on the amount of base exchanging power present. In general the base exchange bodies may be divided into two main categories so two-component; and mult-i-component zeolites, i. e., base exchange bodies containing chemically combined silicon in their nucleus and non-siliceous base exchange bodies. in which all of the silicon is replaced by other is to say metallates and silicates, '(usingthe.

' term metallat'e ina somewhat broader sense as will be defined further on in the description) or metal salts and silicates. Frequently more than one member ofa'type may enter into reaction, that is to say a silicate may react with more than one metallate or more than one metal salt, The multi-component zeolites are the reaction products of'at least P three types of components, that is to say at least one silicate, at least one metallate, and

at least one metal salt. v The base exchange bodies, both zeolites suitable acidic or amphoteric metal oxides.

and non-siliceous base exchange bodies, may be associated with diluents-preferablyinthe form of a physically homogeneous structure, as will be. described below.- Either diluted or undiluted baseexchange bodies may be present in the contact masses used in the present invention, or their derivatives may be present, but it should be understood that wherever .base exchange bodies are referred -to' both diluted and undiluted products'are included. v i

Base exchange bodies, both: zeolites and non-siliceous base exchange bodies, may also be transformed into derivatives which p'0ssess many of the chemical and most of the physical characteristics of the parent base exchange bodies. Such derivatives may be salt-like bodies, that is to say the reaction products of base exchange bodies with compounds containing anions capable of react.- ing with the base exchange bodies'to form products which possess many of thepropem ties of salts. A further class of derivatives are the acid leached base exchan e bodies. When a base exchange ,body is su jected to 7'5 leaching by acids, particularly dilute mineral acids, the exchangeable bases are first gradually removed. The resulting products contain both vthe more basic and more acidic components of the non-exchangeable nucleus of the base-exchange body, with or without a portion of the exchangeable bases. As the leaching is carried on further, more and more of the relatively positive components of the nonpexchangeable nucleus are removed, and if. carried to completion the leached product .contains only'the relatively acid components of the non-exchangeable nucleus. In the case of zeolites the finalproduct from long continued leaching is a complex silicic acidwhich has many of the physical properties of the original base exchange body. Inthe'description and claims the class of base exchange bodies and their derivatives will be referred to by the generic term permutogenetic roducts. Catalytically active components may be associated with diluted or undiluted. permutogenetic bodies in four main forms, as follows :(1) They may be'physically admixed with or impregnated into the permutogenetic products. (2) They may by physically, homogeneously incorporated into the permutegenetic products before the latter have been completelyformed in the form of eatalytical- 1y active diluent bodies or in the form of diluents which have been impregnated with catalytically active substances. (3) They may be chemically combined with or in the 1 permutogenetic products in non-exchangeable changeable form either during the formation of the base exchange body or by base exchange after formation. Obviously of course the same or different catalytically active component may be present in more than one of 5 the above described forms, and it is an advantage of the present invention that catalytically active substances may be introduced in a wide variety of forms which gives a large field of choice to the catalytic chemist.

While the difierent permutogenetic products may vary widely in their chemical characteristics, they all possess a similar physical structure which is characterized by more or less high porosity, frequently microporosity, and great resistance to high temperatures, and in the case of products which have not been acid leachedto the point of removal of catalytic'ally active components these components are distributed throughout the framework of the products in atomic or molecular dispersion, as will be described in greater detail below, and this chemical homogeneity is one of the important advantages of some of the contact masses of'the present invention.

While three of the methods of combination of the catalytically active substances may be effected with undiluted as well as diluted permutogenetic products, it has been found that for most dehydrogenation reactions homogeneously diluted permutogenetic contact masses are of advantage, particularly where the diluents are of a physical nature such as to exert a desired influence on a catalytic activity of the contact masses, as when, for

example, diluents are rich in silica, which has been found to have an activating power. or where the diluents by reason of high porosity, capillarity, or surface energy may be considered as physical catalysts or activators.

Base exchange bodies used in contact masses of the present invention behave as if they were, products of extremely high molecular weight for catalytically active components can be introduced either into the non-exchangeable nucleus or in the form of exchangeable bases in practically any desirable proportions and the ordinary law ofchemical combining proportions, which in compounds of low molecular weight restricts the proportions in which components can be incorporated chemically, appears to be without force, which makes it reasonable to assume that the molecular weight is so high as to completely mask the effect of the law. It is, of course, possible that the base exchange bodies, or some of them, may be solid solutions of a plurality of related compounds of lower molecular weight. It has not been possible hitherto to definitely settle this question, as base exchange bodies are not readily capable of structural chemical analysis. The present invention is of course not limited to any theory, but irrespective of the underlying reasons the fact that cat-alytically active components may be chemically introduced in any desired proportions is of enormous importance to the catalytic chemist and gives him the power to produce an almost unlimited number of finely and gradually toned catalyst-s or contact masses for the dehydrogenation of organic compounds and in all cases the contact masses produced are highly effective by reason of the desirable physical structure of the permutogenetic products con tained therein and the wide limits of homogeneous dilution of catalytically active molecules or atoms with resulting uniformity and smoothness of action, which is of great importance, particularly in the sensitive reactions for which contact masses used in the present invention are peculiarly adapted.

In addition to the important characteristics with which permutogenetic products endow the contact masses of the present invention, ithas been found that for many of the reactions coming within the scope of the present invention it is desirable to stabilize the contact masses, and this may be effected by associating ,with the permutogenetic products or incorporating or forming therein compounds of the alkali forming metals, that is to say the alkali metals, the alkaline earth metals, and the strongly basic earth metals. These compounds appear to slow up or smooth out the catalyticreaction, and will be referred to throughout this specification as stabilizers. The stabilizers may be non-alkaline, weakly alkaline or strongly alkaline, depending on the reaction products and on the nature of the catalytically active components used. It is a great advantage of the present invention that in the normal formation of base exchange bodies alkali forn'iing metal oxides are present as exchangeable bases, and

whether used withoutacid treatment or treatt ed with acid, they form stabilizers which are combined in or associated with the resulting permutogenetic products in an extremely fine state of division in which the stabilizers are peculiarly active. Thus, base exchange bodies containing alkali forming metal exchangeable bases may be considered as complex stabilizers.

In addition to the use of stabilizers, which are important in a large number of splitting reactions included in the scope of the present invention, it has been found that the stabilizer action and the overall efiiciency of the contact masses can in many cases begreatly increased or enhanced by the association therewith or chemical combination therein of elements or radicals or groups which are catalytically active but do not possess specific catalytic activity for the particular reaction to be carried out. Many reactions are aided by the presence of catalysts favoring other types of reactions, such as oxidations, reductions, and the like which are not specific dehydrogenation catalysts. Such catalysts or catalytic components which are not specific catalysts for the reaction in which they are being used under the reaction conditions obtaining will be referred to throughout the specification as stabilizer promoters, as they appear to enhance the toning effect which can be achieved by stabilizers. The use of this expression should, however, in no sense be taken to limit the ex ression to any particular theory of action 0 these non-specific catalysts and in fact in some cases stabilizer promoters may be present where there are no stabilizers.

The tremendous range of chemical groups which may be combined in or with or incorporated in permuto enetic products permits a wide choice of stabilizer promoters as well as specific catalysts, and permits their asso ciation with the contact masses in an extremely homogeneous and catalytically eflicient form. Thus, many base exchange bodies "or their derivatives may be considered as complex catalysts, stabilizers andstabilizer promoters, as all of these elements may be present in the same chemical compound and sharing the advantages flowing from its desirable physical structure and chemical properties. of course both stabilizer and stabilizer promoters maybe mixed partly or wholly with permutogenetic products and a single stabilizer or single stabilizer promoter may be present 'partly in physical admixture and partly in chemical combination, as will'be clear to the'skilled base exchange chemist.

The base'exchange bodies which form the important componentsor initial material for derivatives in contactmasses of the present invention may be prepared by any of the well known methods. Thus, for example, twocomponent zeolites may be prepared by wet methods in which the metallate components or metal salt components, part. or all of which may be catalytically active,-are caused to re act with soluble silicates to form zeolites of alumino silicate or aluminum double silicate types, or the components may be fused, preferably in the presence of fluxes. It should be understood that under the term metallate is included not only the alkaline solutions of amphoteric metal oxides or hydroxides but wet methods, the final reduction product must be alkaline to litmus, and for'products of high base exchanging power it should be neutral or alkaline to phenolphthalein. For the purpose of producing base exchange bodies to be used in the preparation of contact masses of the present invention it is sometimes unnecessary to provide high base exchanging power, and for many purposes zeolites formed under conditions resu ting in a final reaction which is acid to phenolphtha- 'lein butalkaline-tov litmus are of advantage. It is not definitely known whether products produced under such circumstances are homogeneous chemical compounds, although in many ways they behave as such. There is, however, reason to believe that in some cases at least mixtures of base exchanging and non-base exchanging polysilicates may be produced. For the purpose of-the present specification a product will be considered as a baseexchange product if it has any base exchange power at all.

It is desirable for many purposes, and particularly where two-component zeolites of high base exchanging power are needed, to add the relatively acid components, for example, metal salts in the case of aluminum double silicate type of silicates,to the relatively more alkaline components such as, .for example, soluble silicates. By these means a continuous alkalinity is insured, and this method may be considered as the preferred method in most cases, but the opposlte procedure is advantageous for certain contact masses and is includedin the invention.

Multi-component zeolites may be prepared by any of the foregoing methods using at least three types of components,'that is to sav purposes it is advantageous to add the rela-' tively acid components to the relatively alkaline components in order to insure continu- 1011s alkaline reaction. The multi-compone'nt zeolites producedvary in-their nature, depending on the proportion of the difier'ent reacting components. Thus, where the metallates and silicates predominate over the.

metal salts the resulting products resemble the alumino silicate type of two-component silicates; if the metal salts and silicates predominate over the metallates the products resemble the aluminum double silicate type of two-component zeolites; and, finally, if'the metalllates and metal salts predominate over the silicates the resulting product resembles more or less non-siliceous base exchange bod ies. It will be clear that there is no sharp defining line between the three types of multicomponent zeolites, and one shades into the other as the proportions of the different comtions between silicates and other metal oxide components, two or more oxymetal compounds are caused to react; in general, at least one will be a metallate and at least'one a metal salt, or in some cases it is possible to bring about action between. two different met-allates in which one negative radical is more acidic than the other. It is possible to produce non-siliceous base exchange bodies of non-siliceous base exchange bodies.

in which a plurality of metal oxides is present. It is also possible to produce non-siliceous base exchange bodies in which a single metal'is present. Thus, for example, some metals may be sufficiently amphoteric in character to form both metallates and metal salts which are capable of reacting with each other to produce base exchange bodies.

A special method of producing non-siliceous base'exchange bodies consists in the gradual neutralization of strongly alkaline salts of the oxyacidsof metal elements of the fifth and sixth groups in stages of oxidation in which they are. sufficiently amphoteric. The neutralization of other strongly alkaline metallates may also bring about formatli pln e converse method, whereby non-alkaline salts of suitable metals aregradually treated with alkaline until the reaction is sufficiently alkaline to permit the formation of base ex change bodies, may also be used.

Many metals are capable of entering into the base exchange formation only in certain Stages of oxidation, and it is sometimes necessary to introduce such metals in a stage of oxidation different from that desired in the final base exchange body, a change of stage of oxidation being preferably effected during the formation of the base exchange body. Certain other elements may be incorporated in the form-of complex com pounds of the most various types, such as, for example, ammonia complexes and the like.

In addition to the artificial base exchange bodies briefly described above, natural base exchange bodies, such as nepheline, leucite, feldspar, and the) like, maybe used.

The most important contact masses for many dehydrogenation reactions contain permutogenetic products in which preferably the diluents are homogeneously incorporated slag wool; cements; sand; silica gel; pulverized earthenware; fullers earth; talc; lass powder; pumice meal; asbestos; grap ite; activated carbon; quartz meal; various pulverized minerals rich in quartz; metal powders and metal alloy powders; salts of oxymetal acids such as tungst'ates, vanadates, chromates, uranates, manganates, cerates, molybdates, etc., and particularly copper salts of the above; silicates, such as copper silicate, iron silicate, nicked silicate, cobalt silicate, aluminum silicate, titanium silicate; minerals or ores especially those rich in copper, etc. Finely divided diluents are of great advantage, especially when the average particle size is less than 60 microns. in which case the diluents possess high surface energy which increases the adsorptive and adsorptive capacity of the contact mass the diffusion speed and porosity. These finely divided diluents may be consideredas physical catalysts or activators. Diluted ,permutogenetic bodies may also be finely divided and used as part or all of the diluents of other base exchange bodies. 7

The following nine methods are the most effective for the introduction of diluents, but any other suitable methods can be used.

, (1) The diluents may be mixed with one or more liquid components of the base exchange bodies to be formed when the latter are prepared by wet methods.

(2) Components, either catalytically active, stabilizer promoters, or others, may be base exchange bodies of any suitable methods of incorporation.

(3) Diluents may be mixed with base exchange bodies when the latter are still in the form of gels by kneading or stirring, in which case the base exchange gel behaves as an adhesive. 'The homogeneity and'uniformity of the distribution of the diluents is of course i not quite so great by this method as by method (1), but for the dehydrogenation of organic compounds extreme uniformity is not essential.

(4) Diluents may be formed during the formation of the base exchange bodies by mixing suitable compounds with the components of the base exchange bodies so that the diluent particles are precipitated during diluents, as, for example, with heavy metal oxides.

(6) Preformed base exchange bodies, di-

luted or undiluted artificial or natural, can be impregnated with true or colloidal solutions of .catalytically efiective components and then dried.

(7 A preformed base exchange-body, diluted" or undiluted, may be im reg'nated with a plurality of solutions whic react therein to precipitate, any desired diluents.

(8) Soluble diluent compounds may be added to the components forming a base exchange body, which, after formation, retains the compounds in solution and is dried without washing, or is treated to precipitate the compounds. a

(9) Natural base exchange bodies or artificial base exchange bodies, diluted orundiluted, or their derivatives, mav be impregnated with solutions of the desired compounds, which are then precipitated by means of reactive gases.

The nucleus or non-exchangeable portion of the molecules of the base exchange bodies is ordinarily considered to consist of two types of oxides, namely, relative-basic, metal oxides, usually amphoteric, and relatively acidic oxides, such as SiO some amphoteric metal oxides and some metal oxides which have a distinctly acid character; The nucleus behaves as a single anion and cannot be split by ordinary chemical means, but it is advantageous to consider the two portlons of the nucleus as the basic andacidic portions, bearing in mind of course that the nucleus behaves as a single group. The metal comthey may be stabilizers, or 1 they stabilizer promotors. The. may be introduced 1 pounds which are capable of formingthe basic portion of the nucleus are those-of the e following metals :copper,- silver.- gold, bismuth, beryllium, zinc, cadmium, boron, aluminum, some rare earths, titanium, zirconium, tin, lead, thorium, niobium, antimony, tantalum, chromium, molybdenum, tungsten, uranium, vanadium, manganese, iron, nickel, cobalt, platinum, palladium. Compounds of these elements may be introduced singly or in mixtures, in any desired proportions, and may be in the form of simple or complex ions. It should be understood that some of the ele-' ments in certain stages of oxidation may be introduced either as metallates or metal salts; others may be introduced in only one form; and still others may be introduced in a stage of oxidation other than that desired in the final base exchan e body, or in the form J of complex compoun s. Among the complex iouogens are ammonia, hydrocyanic acid, oxalic acid, formic acid, tartaric acid, citric acid, glycerine, and the like.

Many of the metals are specific catalysts, others are stabilizers, and still others are stabilizer promoters. Naturally the status of an element as catalyst or stabilizer promoter will vary with the particular reaction for which the final contact mass is to be used, and-the choice of catalysts and stabilizer promoters, together with the proportions, will be determined by the particular organic dehydrogenation reaction for which the contact mass is to beused.

Examples of components forming the relatively acid portion of the base exchange nucleus are alkali metal silicates which are soluble in alkali, and alkali metal salts of ac1ds,.such as those of boron, phosphorus,

nitrogen, tin, titanium, vanadium, tungsten, chromium, niobium, tantalum, uranium, antimony, manganese, etc.

The exchangeable bases of .the' base exchange bodies may be substituted by base exchange, and the elements which can be introduced singly or in admixture by base ex change are the. following :--copper, silver, gold, ammonium,-beryllium, calcium, manganese, caesium, potassium, sodium, zinc, strontium, cadmium, barium, lead, aluminum, scandium, titanium, zirconium, tin, antimony, thorium, vanadium, lithium, rubidium, thallium, bismuth, chromium, uranium, manganese, iron, cobalt, nickel, ruthenium, palladium, platinum and cerium.

, Depending on the reactions in which. the contact mass is to be used, the exchangeable bases introduced may be specific catalysts, 'may be as simple ions or as complex ions, and may enhance the catalytic activity of the final conil'gact mass, improve its physical strength, or 0th. Y

As has been described above, base exchange bodies can be caused to react with compounds containing acidic radicals capable of forming therewith salt-like bodies. The radicals may be present in the form of simple acid radicals, polyacid radicals or complex acid radicals, andinclude radicals contalning the following elements :chromium, vanadium, tungsten, uranium, molybdenum, manganese, tantalum, niobium, antimony, selenium, tellurium, phosphorus, bismuth, tin, chlorine, platinum, boron. Among the complex radicals are ferroand ferri-cyanogen, certain ammonia complexes and the like. The amount of acid radicals caused to unite with the base exchange bodies to form salt-like bodies may be varied so that the resulting products may possess the character of acid, neutral or basic salts. Many of these acid radicals are stabilizers or stabilizer promotors for the. dehydrogenation of organic compounds.

The base exchange bodies, diluted or undilutedor some of their salt-like body derivatives, may be treated with acids, such as mineral acids, for example, 52-10% sulfuric, hydrochloric or nitric acids, to remove part or all of the exchangeable bases, or also part or all of the basic portion-of the nucleus.

In thecase of zeolites, the partial leaching with acids, which leaves part or all of the basic portion of the nucleus or even part of the exchangeable bases, does not affect the function of the zeolites as catalysts when they contain catalyti-cally active elements in the basic portion of the nucleus, or in some cases even exchangeable bases, and such partially leached catalysts are of great importance in many reactions] Where the leaching is carried out to completion the advantageous physical structure remains to a considerable extent the same but the remainder is of course a form of silica, or, in the case of zeolites in which part of the silica is replaced by other acidic compounds, a mixture'of the two and usually will not be a specific catalyst for the reactions of the present invention. It serves, however, as an advantageous physical carrier of specific catalysts, and in the case of partially substituted zeolites may also contain stabilizer promoters.

Leached non-siliceous base exchange bodies, either partially or completely leached, may contain catalytically active components and behave as catalysts, stabilizer promoters, or both, and many important catalysts are thus obtained. This is particularly the case for reactions where a relatively alkali-free contact mass is required for best results and where the alkali content of a contact mass containing a base exchange body may be too great for optimum results. Base exchange bodies or their derivatives, diluted or undiluted, may also be coated in the form of films on massive carrier granules or may be impregnated therein. The massive carriers may be inert, activating, or them- Example 22 parts of basic copper carbonate are dissolved in the form of a cuprammonlum compound by means of 10% ammonia water. 10.2 parts of freshly precipitated aluminum hydroxide are dissolved up in sufficient 2 N. sodium hydroxide solution to form a clear sodium aluminate solution, and, finally, 24 parts of copper nitrate containing 8 mols of water are dissolved in 100 parts of water. The cuprammonium carbonate and the sodium aluminate solutions are then mixed together. and 50 parts of kieselguhr are introduced with vigorous agitation. Sufficient copper nitrate solution is then poured into the mixture with vigorous stirring until a gelatinous blue product separates out, the reaction being neutral or slightly alkaline to phenolphthalein. The product is a non-siliceous base exchange body containing sodium,

copper and aluminum, and is diluted with minerals rich in SiO The gel is pressed and dried, preferably 1 at temperatures not exceeding 100 0., broken into fragments and hydrated with water. The contact mass is then ready'for use, but it is advantageous in some cases to leach the hydrated base exchange body before drying for a short time in order to remove part of the exchangeable alkali. The leaching may be effected by trickling 1 to 2% nitric acid over the mass. After leaching the product is again dried and constitutes a well toned contact mass for dehydrogenations. Before use the contact mass may advantageously be given a' preliminary treatment with hydrogen containing gases at 300 1].

Alcohol vapors are passed over the contact mass, the corresponding aldehydes or ketones being produced. Thus, for exam-- ple, ethyl alcohol vapors may be passed over the contact mass at temperatures between 200 and 300 (1., and are readily dehydrogenated to ,acetaldehyde. Similarly, cyclohexanol can be dehydrogenated to cyclohexanone at 220300 (3., while isopropyl alcohol or secondary butyl alcohol can be transformed .into acetone or methylethylketone respectively at 300-400 C. The same contact mass can be used for the dehydrogenation of benzvl alcohol, producing benzaldeh'yde as the main product.

' The dehydrogenations have been described as being carried out at ordinary pressure which is the most economical in the majority of cases. However, the reactions may be carried out at elevated pressures or under a vacuum.

In the claims the term permutogenetic covers base exchange bodies, silicious or nonsilicious. the products obtained by the acid leaching of these base exchange bodies and the salt-like bodies obtained by the reaction of these base exchange bodies with compounds the acid radicals of which are capable of reacting with the base exchange bodies to produce products which show most of the properties of salts. When so used in the claims, the term permutogenetic will have no other meaning.

This application is a division of my prior application Serial No. 267,134, filed April 3,1928.

What is claimed as new is:

1. A method of catalytic dehydrogenation, whichfcomprises subjecting an organic compound containing removable hydrogen to the action of a dehydrogenation contact mass containing a permutogenet ic body.

2. A method of dehydrogenation, which comprises vaporizing organic compounds containing removable hydrogen and subjecting the vapors to the action ofa dehydrogenation contact mass contalnlng a permuotogenetic body.

3. A method of dehydrogenating compounds containing an OH group to carbonyl compounds, whichcomprises vaporizing the compounds containing the OH group and subjecting the vapors to the action of a dehydro genatlon contact mass containing a permutogenetic body.

4. A method of dehydrogenating alcohols to" carbonyl compounds, which. comprises vaporizing the alcoholsand subjecting the vapors to the action of a dehydrogenation contact mass containing a permutogenetic body. 7

5.. A method of dehydrogenating primary alcohols to aldehydes, which comprises vaporizing the alcohols and subjecting their vapors to the action of a dehydrogenation contact mass containing a permutogenetic body.

6. A method of catalytic dehydrogenation, which comprises subjecting an organic compound containing removable hydrogen to the action of a dehydrogenation contact {)nass containing a diluted permutogenetic 7. A method of dehydrogenation, which comprises vaporizing organic compounds containing removable hydrogen and subjecting the vapors'to the action of a dehydropounds containing an OH group to carbonyl componds, which comprises vaporizing the compounds-containing the OH group and subjecting the vapors to the action of a de-' hydrogenation contact mass containing a genetic body.

10. A method of dehydrogenating primary alcohols to aldehydes, which comprises vaporizing the alcohols and subjecting their vapors to the action of a dehydrogenation contact mass containing a-diluted permutogenetic body.

11. A method according to claim 1 in which at least one catalytically effective component of the contact mass is present in the permutogenetic body in non-exchangeable orm.

12. A method according to claim 3 in' which at least one catalytically effective component of the contact mass is present in the permutogenetic body in non-exchangeable form.

13. A method according to claim 4 in which at least one catalytically efi'ective component of the contact mass is present in the pcrmutogenetic body in non-exchangeable form.

14. A method according to claim 5 in which at least one catalytically effective com- 7:

ponent of the contact mass is present in the permutogenetic body in non-exchangeable form.

Signed at Pittsburgh, Pennsylvania, this genation contact mass containing a diluted permutogenetic body.

8. A method of dehydrogenating com- 

